ScienceToday

How did Mars lose its atmosphere?

“We’ve determined that most of the gas ever present in the Mars atmosphere has been lost to space,” said Bruce Jakosky, principal investigator for the Mars Atmosphere and Volatile Evolution Mission (MAVEN), University of Colorado in Boulder.

Mars was once a warm, wet planet with an atmosphere as thick as Earth’s, but unfortunately, those days are just a memory now. The Red Planet is now a dusty old place due to atmospheric erosion, caused by a phenomenon known as ‘sputtering.’ This phenomenon occurs as solar wind knock atoms carry ions out of the atmosphere and into space.

“This discovery is a significant step toward unraveling the mystery of Mars’ past environments,“ said Elsayed Talaat, MAVEN Program Scientist, at NASA Headquarters in Washington. “In a broader context, this information teaches us about the processes that can change a planet’s habitability over time.”

 

How long would it take to terraform Mars?

Terraforming involves changing the surface and atmosphere of a planet to be more like Earth and therefore a place where we, humans, could live. However, we need carbon dioxide in order to terraform it, and Mars just doesn’t provide enough. So before we find a way, the answer to that question is somewhere between a very, very looooong period and never.

“Our results suggest that there is not enough CO2 remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere; in addition, most of the CO2 gas is not accessible and could not be readily mobilized. As a result, terraforming Mars is not possible using present-day technology,” said Jakosky.

 

How far is Mars from the Sun?

Mars is the fourth planet from the Sun, having what is called an eccentric orbit, meaning that it’s not completely circular around the Sun. As I said before, the distance between the two is constantly changing, but the average distance would be 154 million miles (249 million km) from the sun.